What is the primary role of the peripheral nervous system?

• A. The nerves transmit motor signals from the CNS to the muscles involved in a movement and then send sensory information to the CNS to provide feedback on the movement.
• B. The brain processes all information and controls movement directly without spinal involvement.
• C. The peripheral nervous system only processes reflexes.
• D. Muscles themselves coordinate movements without nerves.

Answer: (A)

The peripheral nervous system acts as the communication network between the central nervous system and the rest of the body. It carries motor commands from the brain and spinal cord to the muscles, enabling movement, and it brings sensory information from receptors back to the CNS so the brain can monitor and adjust actions. This bidirectional flow is what allows coordinated movement and responsive control, with the PNS including both somatic (voluntary) and autonomic (involuntary) pathways.

Think of it this way: the brain and spinal cord decide what to do, but the PNS is what actually delivers those instructions to the muscles and relays tissue and environment information back to the brain for refinement. The other options misstate the role—movement can’t be controlled without nerves, the CNS doesn’t process all information in isolation, and the PNS isn’t limited to reflexes.